


Just a One Time Thing

by PineTrain



Category: Gravity Falls
Genre: Alternate Universe - Reverse Falls, Blow Jobs, Deepthroating, F/M, Facial, Reverse Mabel Pines, Seduction
Language: English
Status: Completed
Published: 2018-03-04
Updated: 2018-03-04
Packaged: 2019-03-26 17:14:08
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,776
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13862235
Author URL: https://archiveofourown.org/users/PineTrain/pseuds/PineTrain
Summary: Call it a spiritual sequel to Blue Temptation





	Just a One Time Thing

**Author's Note:**

> Call it a spiritual sequel to Blue Temptation

Branch. Root. Rock. Stream.

Dipper’s eyes expertly caught each and every obstacle as he raced through the forest. He should be in an area he knew, but things were altered. Still, his skill helped him dip, dive, and dodge his way through the foliage despite the magical interference with reality.

“Vwoop!”

He heard the word and immediately leaped into a roll, his eyes catching sight of a glowing blue root that had sprung from the ground. As he came to his feet, though, he found another blue problem.

“Plah!” Mabel exclaimed, wrapping her arms around him as his momentum carried him into her. She rocked back a tad then set him on his feet without releasing her grip. “A nice leap, ‘Dipper’” she said, sardonicism dripping with his name. “Mason would be proud.”

“Keh!” Dipper coughed to the side as he recovered. “Good to know,” he said sarcastically.

“Hee! You do have a bit of him in you! Oh, it’s so cute!” Mabel giggled. “There's some of her in me, right? I'm always so curious!”

“Uh, yeah, I guess,” Dipper answered, somewhat confused about how this was going. When he'd escaped the room his alternate self and this Mabel had put him in, he'd expected to be chased when he escaped. He even expected to be caught, considering what he'd seen after he'd accidentally slipped into their universe. He was defiant, and so he expected punishment, not whatever was in this Mabel’s eyes right now.

“Damn, damn, damnity damn, I could just eat you up,” she giggled again. “Oh, if he was like this every once in a while,” she said, stroking his cheek in an oddly affectionate way.

“Um, what?” Dipper asked, completely confused. He flinched as she pressed her body to him.

“Oh? Scared little rabbit?” she asked teasingly.

“I- what are you even doing?”

Mabel cocked her head curiously. “You mean you don't…? You do have your own Mabel, right? You're not from a universe where I don't exist?”

“Yeah, I have a Mabel,” Dipper answered. “What's that got to do with you?”

Her eyebrows sprang up. “You don't! With her! You're a virgin!”

“Wh- I'm not a vir-” Dipper choked as he realized she didn't just mean sex when she used the word. Rather, sex with a particular person.

A sly grin grew on her face. “It's been forever since a virgin stumbled into our universe…”

“You mean you and, uh, this-universe-me…?” he asked, incredulous.

“Oh, yes we do, virgin,” she whispered as she leaned by his ear. “Us and a lot of us’s. You're a rare find.”

“Wha- bullshit!” Dipper exclaimed. He tried to shove her away, but she barely nudged to the sound of quiet hum.

“You’ve never wondered? Never thought of it? Not even when you were in the midst of puberty, erections here and there, all needing tending and so little material to do it with?”

“What?” he asked, initially confused but quickly understanding. “No! I had the internet!”

“And when you didn't? When the Shack lost power? When you camped? Just you and her?”

“N-no!” Dipper said, unsure why he was even entertaining these questions. He was feeling very uncomfortable with her body on his.

“Oh… you are a rare catch. A liar who doesn't fold. I like that…” Mabel said, kissing his jaw.

"I'm not lying! I'd never think of Mabel that way!” he said defiantly.

“Never think of me what way?” she asked innocently with a pouty face and deep blue eyes.

“You're not Mabel!”

“Pff! Of course I am,” she laughed. “I'm just not ‘your’ Mabel. I could be, though, if you know what I mean.”

Dipper didn't like the waggle of her eyebrows. It was too familiar, too easy to see ‘his’ Mabel in this odd doppelganger. “N-no…” he said as sternly as his wavering voice could.

“Hm, fine,” she said, releasing him. He stumbled in surprise at how quickly it ended. She looked at him disparagingly. “We aren't rapists. No means no and all.”

“Oh, um, that's good of you,” Dipper said, confused at the tonal shift of the situation. “Wait, ‘we’?”

Mabel rolled her eyes. “That's one thing you virgins have in common with the rest of them: You think it's just one of us cheating on the other or whatever. So self-absorbed, Mabels and Dippers alike…”

“W- so you're with him and you don't care if he's with another girl?”

“I just tried to be with you. What, you think YOU would be good enough to replace him? We get a bit jealous, but that makes the make-up session more fun,” Mabel said with a smile as she shifted her legs back and forth a bit.

“I, uh, okay, cool,” Dipper said, unsure what else to do.

“Did she slip in with you?” Mabel asked, holding her elbow as she touched a finger to her chin thoughtfully.

“What?”

“Your Mabel. Sometimes you come alone, sometimes in pairs, sometimes together but separate. Our universe does seem to be a hub of sorts.”

Her sex life made more sense knowing that, Dipper supposed. “It was just me. Why?”

“Just needed to know if we had to hunt her down. It’s easier to send you back together, obviously. That's why we put you in the room. You Dippers always flip out and try to run away, so it's at least an impediment that stops a few. In any case, if it’s just you, we can get right to sending you back.”

“Oh, right. Makes sense, I guess.” Dipper suddenly felt like he was talking to a travel agent or something.

“But you're sure it was just you who came here, right? I wouldn't want some poor other-me wandering around confused and alone in a different universe without her brother to help her.”

“I mean, yeah, it should just be me,” Dipper said.

“Should?”

“I can't just say for certain. I fell in a hole in the woods and ended up here. Mabel wasn't with me. So yeah, it should just be me.”

“Ah,” Mabel said, setting a comforting hand on his shoulder, “you're from one of _those_ universes.”

“Wh- what's that mean?” he asked indignantly.

“Where we have a bad relationship and a Mabel wouldn't look for her Dipper if he didn't come home. It's okay, you're not the first I've met.”

“Mabel would totally look for me! We don't have a bad relationship! She loves me!” This Mabel cocked her head. “Y-you know what I mean by that…” Dipper muttered.

“Hm, well if she loves you so much, she might have stumbled into the same little hole you did. Don't worry, we'll find her soon enough. My Mason has been looking about the area we found you just in case. Who knows, he might already have found her. Maybe more.”

“More? Wait, what?”

Mabel shrugged. “You said no to me, but she could have said yes to him. She loves you after all, and Mason technically is you.”

“Wh-pthh-” Dipper sputtered, incapable of proper words. “She wouldn't!” he managed after a moment to recover.

“Hum,” Mabel shrugged again. “I guess. You know her better than me. I do know Mason, though. He can be quite convincing, especially to people who are reluctant to admit what they want.”

Dipper frowned, remembering how this Mabel described their relationship as rare. She hadn't been wrong about him being a liar, what if she wasn't wrong about his Mabel falling for her Dipper, or Mason, as it were?

“Oh? Does it bother you?” she asked innocently. “Did you just think ‘my mabel’ and ‘her dipper’?” He flinched at how well she read him. “It's okay, she’s probably not here. I mean that honestly. We know the kind of portal you fell through. They're usually one person. “Usually” being the keyword, so Mason is indeed looking for her, but he’s actually more of a long-term seductor. There's no worry of him snatching her from you.”

“I- I wasn't worried about that! Mabel can be with whoever she wants!”

“Even if it's you? Oh! I mean Mason?”

“Er, well, sure, I- I guess…” Dipper trailed off, feeling confused.

“Hmm, well, he does have his more… assertive days. Maybe today is one?” Mabel mused. “Considering you're a virgin,” she gave him a condescending up-down, “I imagine you two are a fairly innocent iteration. I can just see how he'd handle it

“He'd be coolly confident, complementary to a fault. She'd chastise him with a giggle while she wished she’d heard the same words from your mouth. It'd take her a moment or two to notice how close he was, how his hand wrapped her shoulder, how easy it was to let him pull her in.

“She loves you, after all, and this is you, but a you that she will never see again. Maybe she could indulge in a forbidden fantasy she's always had? Just this once, in a place where no one will ever know. One of his hands is at the back of her head, guiding her lips to what she wants now, the other is squeezing her ass, telling her she’ll have what else she wants later…

“But that's just my guess. What do you think? Hm?”

Dipper blinked and shook his head, the mental image still faintly in his eyes. He looked down and saw Mabel pressed up against him with a cheerful, almost oblivious smile, as if she hadn’t just given him the intro to an erotic fanfic about themselves. She started humming the Jeopardy tune.

“Mabel wouldn't do that…” he muttered.

“Maybe not, but she can do what she wants, right? So what's the difference? Same for you. What's a one time thing? Hell, maybe it’ll help your little liar self not think so much about her if you have a memory of me instead.”

Dipper stared into her glinting blue eyes, hypnotized by the eagerness they carried. It was so familiar, so Mabel. Just like the cheeky grin she had as she leaned up and pecked his cheek. He tried to step back and bumped into a tree. She must have moved him there while he was distracted by her story.

“It's no big deal,” she murmured against his neck, kissing it gently. “Just a one time thing.”

“J-just a one time thing…” he echoed in a whisper. He meant it as a question, but even if he'd properly said it that way it still would've been more of an answer.

“Hee!” Mabel giggled, lifting her mouth to his ear. “You can hold my head as hard as you want, but I worked hard on my makeup…”

Dipper connected the dots and caught her drift. He thought they'd just be kissing, like his doppelganger’s first hand had indicated in her story, but now he remembered where the second had been. “W-wait! I didn't mean-”

“Just a one time thing, what's the difference?” Mabel repeated, dropping to her knees. “See,” she said, unfastening his shorts, “this way I won't pop your cherry, virgin.” His cock sprang free as she yanked them down. “Your Mabel gets to do that, but I get the first taste…”

He gasped as her mouth enveloped the head of his cock. Mabel immediately began bobbing in quick, short motions that drifted further and further down his length, her wet lips gradually lubing him. He soon felt a resistance and she paused for a few seconds, humming a quiet tune that made him shiver. He realized it was Jeopardy again.

Pulling off of him, she stared up at Dipper with an impatient expression while she lightly jacked him. With her other hand she grabbed one of his and placed it firmly on her head. Her instructions were clear and she returned her mouth to his cock, repeating her motions exactly, but this time humming the Jeopardy theme the entire time.

It was a little surreal feeling that same resistance just as the tune was ending and Dipper knew he'd never be able to watch the show ever again. Right before the final *bum-bum* she pressed away a tiny bit and sucked in some air, then pushed in as they would have happened. Of course, she didn't actually hum them since his dick was now in her throat.

Dipper trembled, his legs like jelly as he struggled to comprehend how good this felt. Mabel pushed as far as she could, her nose bumping his pelvis and she stayed there for a second or two before pulling all the way back with a gasp and a cough. A line of thick saliva connected her mouth and him and she held one hand under it while the other jacked him as before.

She glared upwards, a harsh lust in her glowing blue eyes, and she gave a small jiggle of her head to remind him of his hand on it. It was no longer an instruction, but a command. Dipper suddenly felt glad this was a one time thing in a different way, afraid to see how deep this Mabel’s sex life really went.

He obliged her, and when her mouth began sinking down his member again he applied pressure the whole way. When she bottomed out and he gasped at the confines of her throat, he felt her begin pulling back. Dipper let her do so, but looking down he saw the same burning glare and understood what she wanted: A fight.

It felt strange, to say the least, looking down at the angry visage of his sister, eyes watery from his cock choking her at her own insistent demand. It was more strange that it was so hot seeing her like this as he forced her down again and again, sloppy and wet sounds emanating from her throat. He didn't think he'd ever forget the sight, nor did he think he'd last much longer looking at it.

Mabel’s throat twitched, and twitched again. The feeling made Dipper go cross-eyed, but she pressed her hands to his thighs and shoved herself off him with a heavy cough. It was the final straw for him and he grunted as his orgasm shook him. His eyes squinted closed while waves of pleasure spread through his body, but he heard Mabel scream an obscenity.

“Makeup, you jackass!” she said venomously as he came down. She knocked his hands from her head and stood up, glaring at him.

Dipper swallowed, unsure how to handle the appearance of his sister’s face covered in cum. “S-sorry! I meant to cum in your throat!” He snapped his hands over his mouth in disbelief he'd actually said that.

Mabel rolled her eyes. “Whatever. I'm pissed now.” She snapped her fingers and a portal opened next to Dipper. “Go fuck your Mabel or something.”

“Wai- wha-oomph!” Dipper uttered as she punted him through it.

The portal closed and Mabel touched her face. Examining the droplet of cum that clung to her finger she tasted it. She frowned slightly, thinking that his Mabel should force him to improve his diet before she did anything like this. With a sigh, she marched off towards the agreed upon location.

Her eyebrows popped up at her brother's appearance when she entered the small clearing. His clothes were amuck and torn, his hair was a mess, and glitter and lipstick were everywhere. “You weren't supposed to have sex with her!” she said angrily.

“I... didn't,” Mason answered quietly. “I'd rather not go into details. You know how your alternate selves can be. I see you got turned into a Jackson Pollock again.”

Mabel grumbled to herself, not enjoying the feeling of drying cum on her face. Still, they'd agreed that they'd meet up just how their partner left them. “To be fair, it's not entirely his fault,” she admitted grumpily. “I let this one deepthroat me and I messed up the timing.”

“Oh, a deepthroat for his first time… that'll be a good match with his Mabel,” Mason said, looking up in thought.

Mabel rolled her eyes just as she had with the other Dipper and grabbed his arm. “Yeah, Mabel’s do crazy stuff, get over it already. I'm pissed and horny and I want to do it in the shower.”

Mason perked up a bit at that, though he pretended to be stoic as always. As they made their way home, Mabel wondered how many Dippers and Mabels they’d actually gotten together with their strange little scheme. She didn't know what Mason saw on the Mabels’ faces before he sent them off, but if the Dippers’ were anything to go by before she kicked them back home, she felt like it was 100% of them.


End file.
